1. Field of the Invention
The present invention is directed to an arrangement for detecting a light signal which is branched from a waveguide and detected by a detector having a detector window.
2. Prior Art
Arrangements for branching off a signal from an optical waveguide, such as an optical fiber, and detecting the signal with a detector are known and disclosed in German Offenlegungsschrift No. 25 50 523, which is based on three U.S. patent applications that matured into U.S. Pat. Nos. 3,931,518, 3,936,631 and 3,982,123. These arrangements are used as devices for scanning signals carried in waveguides. For this purpose, the waveguide is curved by means of a mechanical pressing or bending apparatus to such an extent that part of the signal carried in the waveguide is discharged from it laterally and the signal thus branched off is received by the detector. However, since a detector window does not extend over the entire curvature of the waveguide and thus the radiating surface, only part of the branched off signal is received. Moreover, the branched off signal can be generated only in those cases where the pressing apparatus has been actuated to bend the waveguide. While the pressing of the waveguide to bend it may be acceptable for practical applications on one hand, on the other hand the continual pressing of the fiber raises problems with uncontrolled fiber rupture which is inherent with this practice.